clink! is a project that incorporates the idea of coloring liquids in cocktail
glasses with light. The project consists of individual cocktail glasses, each
equipped with three LEDs (red, green and blue). Clinking two glasses mixes the
respective colors (based on the principle of additive color mixing). For example,
clinking a blue and a red cocktail glass changes the color of both glasses to
magenta. In contrast to other projects dealing with augmented interpersonal visual
communication, clink! allows highly controllable interactions, visually
representing the participants in a very subtle way.

clink!paper -
June 2002 (PDF document, 220K). Note that some points of the project have
been revised since 2002.

Inspiration
In one of the decisive scenes of the movie "Suspicion", the glass of milk
that Cary Grant brings upstairs to Joan Fontaine appears to glow. Interviewed by
Francois Truffaut, Hitchcock remarked that this effect was achieved simply by hiding
a light in the milk glass.

Historical Context
The social habit of clinking glasses goes back to medieval times and resulted from
the actual mixing of liquids. In those days, it was not uncommon to poison wine, quite
frequently to get rid of opponents. To prove that his wine was safe, a host would
pour a bit of his guest's wine into his own glass and drink it first. If the guest
trusted his host he would just clink glasses when the host offered his glass for a
sample. The 'clinking' of glasses became a sign of trust and honesty.

Social Contextclink! can be seen in the tradition of projects dealing with technology
mediated visual communication expressing personal affinity. Many existing projects
in this field imply a strategy where the participant cannot consciously influence
the display of his or her own personality/character. Mood rings from the late
seventies or, more recently, Diller and Scofidio's Brain Coats within the
Blur project for the Swiss EXPO 2002 are such examples. The critique can be
brought forward that if the participant is not fully aware of surrendering to the
visual representation of his or her personality (not even taking into consideration
the possibility of unprecise representation) disappointment or intimidation might be
the result.

Source: Diller and Scofidio: Blur: the making of nothing, p.216

clink! uses a different approach in visualizing social interactions: it allows a
technically mediated visual communication in a much more subtle yet highly
controllable way, displaying a participant's character/personality indirectly but
very precisely.

In the course of a cocktial party, clink! also allows a realtime visual
overview of social behavior and group links, especially when watching the party
guests from an elevated point of view.

Technical Issues
The realization of clink! is challenging, yet it poses
questions that are both artistically and technically interesting. For example,
the clinking of two cocktail glasses triggers the mixing of the two colors, but
what sensor can detect this event in a reliable fashion? Artistically interesting in
this case is the clinking as a trigger event. It leads to questions such as: are there
other collision events that can be used as a trigger for an aesthetic process? Bumping
into someone else in the street, dropping something on the floor, a fender bender...

More specifically, the following technical issues currently exist:

Design: which container will hold all the technical components? Since many
well-designed cocktail glasses already exist, the technical parts should not be part of
the cocktail glass itself. Instead, an add-on to the cocktail glass, such as a
stirring stick (Figure 2) or an olive-sized container (Figure 3) should house the
electronic components.

Sensor: in the first demo version, the clink! glasses were equipped with
conductive rims. From the rim, a wire led into the liquid which was used as a body
holding an electrostatic charge. A capacitance sensor could detect a clinking event
based on the increase of electrostatic charge in either liquid. Unfortunately, if two
persons touched the rims of their glasses at the same time, the system would also
interpret this as a clinking event... Other options for detecting the touching of two
glasses include the use of an audio frequency sensor or experiments with an accelerometer.
It would be also possible to combine readings of multiple sensors for a more reliable
clink detection.

Wireless data transmission: data needs to be exchanged in the moment of
clinking, for this to happen, both glasses have to send and receive almost
simultaneously. So far, several technical options have been considered, each of which
would need more complex engineering: from IR (a line of sight between two glasses
is required) to RF and inductive coupling.

Miniaturization of technical parts: The module that houses sensor, tri-color
LED, microprocessor and wireless unit needs to be small enough to fit into a cocktail
glass. Atmel has an interesting series of fast yet very small microprocessors (AVR
ATtiny, e.g. ATtiny85), the use of surface-mount parts could save further space, too.

Power suppply: batteries for each module need to be ultra compact and powerful.
If the modules need to be sealed against the liquid and a change of batteries is not
possible, rechargeable batteries that could be charged by inductance could be used.

The following sketch shows the current demo setup which works quite well with two
glasses for demonstration purposes. Unfortunately, it cannot be used in a coktail party
situation. The sensor system has been reduced to a simple +5V digital input/output, and the
wiring of the two glasses it doesn't allow the participants to move around freely.

Presentation of the clink! demo setup in the lecture The Mix, School
of Art Fall Lecture Series, Carnegie Mellon University, Pittsburgh, September 2004.

Presentation of the clink! demo setup in the lecture Responsive Social
Spaces as part of Inside/Outside: Responsive Environments and Ubiquitous
Presence, the Banff New Media Institute, Banff Centre, Canada, August 2004.

Exhibition of the clink! demo setup in conjunction with Casablanca
(video clip) at the NewForms Festival, Roundhouse Community Center Exhibition Hall, Vancouver,
Canada, August 2003.

Paper presentation and initial demo setup with two clink! glasses at the
SIMS02 conference, CREATE/MAT, UC Santa Barbara, June 2002.